Experimental quasispecies evolution with avian coronavirus

• Grant number: 18/12417-7
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2019
• End date: May 31, 2021
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Paulo Eduardo Brandão
• Grantee: Paulo Eduardo Brandão
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Hans Mikael Berg ; Sheila Oliveira de Souza ; Sueli Akemi Taniwaki Miyagi

Abstract

Quasispecies is a term used to describe the collaborative population genetics of multiple sub consensus variants under a dominant genomic sequence of RNA and some DNA viruses. Each variant on the spectrum might show a different fitness, which changes according to the selection pressures such as immune response and host spillovers. For Avian coronavirus (AvCoV), the effects of host shift on the quasispecies evolution has either been assessed with low-coverage sequence methods or at low passage number in cell cultures. Furthermore, the effect of the humoral immunological diversity upon this phenomenon has not been assessed. To cover these aspects, the aims of this project are threefold: to measure the effects of chicken hyperimmune sera against different AvCoV vaccine strains on the fitness of a fixed AvCoV strain in cell culture using qPCR, to assess the quasispecies constitution of this same AvCoV fixed strain after incubation with chicken hyperimmune sera against different AvCoV vaccine strains using deep sequencing and to follow the quasispecies evolution of the AvCoV fixed strain after serial passages in cell culture. To this end, the Beaudette strain of AvCoV will be serially passaged in VERO cells up to the 15th passage and full genome variants and fitness will be assessed with deep-sequencing and qPCR, respectively. In another experiment, the Beaudette strain will be incubated with sera from chicken vaccinated with homologous and heterologous AvCoV strains and analyzed likewise. This project is expected to give results on quantitative indicators of coronaviruses quasispecies, both in terms of the fluctuations of the frequencies of each variant and under a range of immune selection pressures as well as insights on the consequences of vaccination for coronavirus-caused diseases. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PAULO E. BRANDÃO; MIKAEL BERG; BEATRIZ A. LEITE; SHEILA O.S. SILVA; SUELI A. TANIWAKI. The order of events on Avian coronavirus life cycle shapes the order of quasispecies evolution during host switches. GENETICS AND MOLECULAR BIOLOGY, v. 45, n. 2, 2022-06-06. (18/12417-7)

BRANDAO, P. E.; BERG, M.; SILVA, S. O. S.; TANIWAKI, S. A.. Emergence of Avian coronavirus Escape Mutants Under Suboptimal Antibody Titers. Journal of Molecular Evolution, v. 90, n. 2, p. 6-pg., 2022-02-23. (18/12417-7)

CONSELHEIRO, JULIANA AMORIM; BARONE, GISELY TOLEDO; MIYAGI, SUELI AKEMI TANIWAKI; SILVA, SHEILA OLIVEIRA DE SOUZA; AGOSTINHO, WASHINGTON CARLOS; AGUIAR, JOANA; BRANDAO, PAULO EDUARDO. Evolution of Rabies Virus Isolates: Virulence Signatures and Effects of Modulation by Neutralizing Antibodies. PATHOGENS, v. 11, n. 12, p. 18-pg., 2022-12-01. (18/12417-7)